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Full text of "The Morphology And Evolution Of The Apes And Man"

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EXTEENAL CHABACTEES  AND  HABITS       87
and when any difficulty arises it is in connection with females.
The hand is long and narrow, and the small thumb only reaches as far as the metacarpo-phalangeal joint of the index finger. The palm is pale, smooth and hairless. The thenar and hypothenar eminences are small or absent, and pads are only present on the terminal phalanges. Flexure lines are well marked, but they are variable, as can be seen from a studv of the illustrations
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published by Beddard (304), Gratiolet $301, Hepburn (82), Sperino (401) and others. The arrangements in a young male animal examined by myself are shown in fig. 19. It will be seen that there are well-marked lines on the interphalangeal joints; three transverse lines cross the palm, and the thenar and hypothenar areas are bounded by curved lines. Three longitudinal lines radiate' inter tbe palm from the junction of the thenar and hypothenar lines. The proximal parts of the digits, with the exception of the thumb, are webbed. The back of the hand and proximal parts of the first phalanges are hairy, and the hairs radiate in all directions from an area over the base of the metacarpal bone of the index finger. And the naked skin on the backs of the penultimate phalanges, which are used in locomotion, is thickened to form oval callosities.
The whole of the palmar aspect of the hand and fingers is covered with papillary ridges running in all directions ; and their arrangement is shown by fine lines in fig. 19. They form loops on the terminal phalanges; on the middle phalanges they are transverse; and on the proximal phalanges they are oblique. The distal part of the palm is occupied by ridges in arches; and the more